PolyMet Expands Board of Directors

HOYT LAKES, MINNESOTA--(Marketwire - March 10, 2011) -PolyMet Mining Corp. (TSX:POM)(NYSE Amex:PLM) ("PolyMet" or the "Company") announced today that it has appointed Alan R. Hodnik and Michael M. Sill to its Board of Directors.

Al Hodnik was named President of ALLETE, Inc. in May 2009 and CEO of that company in May 2010. Since joining ALLETE in 1982, Mr. Hodnik has served as Vice President-Generation Operations, Senior Vice President of Minnesota Power Operations, and Chief Operating Officer. As Chief Operating Officer, he led transmission, distribution, generation, and engineering for all aspects of the Company. Mr. Hodnik was the elected mayor of the City of Aurora, MN from 1988 to 1998. He is a member of the board of Essentia Health - East Region and of the Area Partnership for Economic Expansion (APEX).

Mr. Hodnik has served ALLETE for 29 years, working in a wide variety of positions of increasing responsibility. He brings utility operations, strategic planning, leadership, and broader organizational development experience, as well as a deep understanding of the region served by that company.

Mike Sill has served as President and CEO of Road Machinery & Supplies Co. since 1994, having joined the company in 1988. Road Machinery is a distributor of construction, mining and forestry equipment. Educated at Dartmouth College and J.L. Kellogg Graduate School of Management, Mr. Sill started his career as a financial analyst and commercial lending officer with The Northern Trust Company. He has served on the boards of the Equipment Distributors Association of MN, Associated General Contractors of MN, and the Twin Cities Regional Board of US Bank.

Frank Sims, Co-Chair of PolyMet stated, "I welcome Al and Mike to our board. They bring extensive business experience in the upper Midwest and we look forward to their guidance as we complete the environmental review and permitting process for our NorthMet project."

About PolyMetPolyMet Mining Corp. (www.polymetmining.com) is a publicly-traded mine development company that controls 100% of the NorthMet copper-nickel-precious metals ore body through a long-term lease and owns 100% of the Erie Plant, a large processing facility located approximately six miles from the ore body in the established mining district of the Mesabi Range in northeastern Minnesota. PolyMet Mining Corp. has completed its Definitive Feasibility Study and is seeking environmental and operating permits to enable it to commence production. The NorthMet project is expected to require more than one-and-a-quarter million hours of construction labor and create approximately 360 long-term jobs, a level of activity that will have a significant multiplier effect in the local economy.

POLYMET MINING CORP.

Joe Scipioni, CEO

This news release contains certain forward-looking statements concerning anticipated developments in PolyMet's operations in the future. Forward-looking statements are frequently, but not always, identified by words such as "expects," "anticipates," "believes," "intends," "estimates," "potential," "possible," "projects," "plans," and similar expressions, or statements that events, conditions or results "will," "may," "could," or "should" occur or be achieved or their negatives or other comparable words. These forward-looking statements may include statements regarding our beliefs related to the expected proceeds and closing of the registered direct offering, exploration results and budgets, reserve estimates, mineral resource estimates, work programs, capital expenditures, actions by government authorities, including changes in government regulation, the market price of natural resources, costs, or other statements that are not a statement of fact. Forward-looking statements address future events and conditions and therefore involve inherent risks and uncertainties. Actual results may differ materially from those in the forward-looking statements due to risks facing PolyMet or due to actual facts differing from the assumptions underlying its predictions. PolyMet's forward-looking statements are based on the beliefs, expectations and opinions of management on the date the statements are made, and PolyMet does not assume any obligation to update forward-looking statements if circumstances or management's beliefs, expectations and opinions should change.

Specific reference is made to PolyMet's most recent Annual Report on Form 20-F for the fiscal year ended January 31, 2010 and in our other filings with Canadian securities authorities and the Securities and Exchange Commission, including our Report on Form 6-K providing information with respect to our operations for the nine months ended October 31, 2010 for a discussion of some of the risk factors and other considerations underlying forward-looking statements.

The TSX has not reviewed and does not accept responsibility for the adequacy or accuracy of this release.